BREECH too small?

Hey guys ive got a technical problem.
i was putting on my QEV when i somehow managed to over torque it and break the threads off in the breech (anyone know how to get that out??).
so, i go on ebay and find one for $5 order it and a new qev.
I install everything but i notice that, while the gun will cycle, the bolt isnt pushing through the breech with the proper speed. so i take the bolt out and slide it through my old breech and it does so with relative ease, but when i slide it around in the new breech there is a little more resistance which i think may be causing the problem.
i bought my ion in 2005 and my breech is a dust black whereas this one is the shiny black (presumably from a much newer ion).
So, im thinking that must be the problem is the new breech is sliiiightly smaller and causing the bolt to have more resistance than the old one.
i tried jacking the input pressure up to 190 or so but that didnt make a difference. used plenty of lube as well.
i think even a slightly smaller o-ring on the bolt would do the trick...

Any suggestions? If you could even offer a way to remove the broken qev threads from my old breech that would be fantastic.
thanks.

You can get the old one out by gluing a allen key into the QEV stem and generally it will come out. Also, you could alternatively wedge an allen key into the hole and try to turn it out of there like that.

DSDM Try changing the o-rings in the breech. take them out of your old one and put them in your new one.

i tried this, but i had a real hard time getting to the one nearest the feedneck (w/feedneck removed) as this would be the one causing the trouble. is there an easy way to remove that o-ring from the breech?

update: i removed the ball detents and the bolt cycled fine when in rapid fire, but if single firing it still had some trouble - this was a great improvement from before. this is telling me that the bolt is running into too much resistance in the breech. maybe need newer detents? and replace the o-rings?

or how about this: does anyone know where to find a cheap *** breech for an older ('05) ION?